Source code for statsmodels.iolib.foreign

"""
Input/Output tools for working with binary data.

See Also
--------
numpy.lib.io
"""
import numpy as np

from statsmodels.iolib.openfile import get_file_obj


[docs] def savetxt(fname, X, names=None, fmt='%.18e', delimiter=' '): """ Save an array to a text file. This is just a copy of numpy.savetxt patched to support structured arrays or a header of names. Does not include py3 support now in savetxt. Parameters ---------- fname : filename or file handle If the filename ends in ``.gz``, the file is automatically saved in compressed gzip format. `loadtxt` understands gzipped files transparently. X : array_like Data to be saved to a text file. names : list, optional If given names will be the column header in the text file. fmt : str or sequence of strs A single format (%10.5f), a sequence of formats, or a multi-format string, e.g. 'Iteration %d -- %10.5f', in which case `delimiter` is ignored. delimiter : str Character separating columns. See Also -------- save : Save an array to a binary file in NumPy ``.npy`` format savez : Save several arrays into a ``.npz`` compressed archive Notes ----- Further explanation of the `fmt` parameter (``%[flag]width[.precision]specifier``): flags: ``-`` : left justify ``+`` : Forces to preceed result with + or -. ``0`` : Left pad the number with zeros instead of space (see width). width: Minimum number of characters to be printed. The value is not truncated if it has more characters. precision: - For integer specifiers (eg. ``d,i,o,x``), the minimum number of digits. - For ``e, E`` and ``f`` specifiers, the number of digits to print after the decimal point. - For ``g`` and ``G``, the maximum number of significant digits. - For ``s``, the maximum number of characters. specifiers: ``c`` : character ``d`` or ``i`` : signed decimal integer ``e`` or ``E`` : scientific notation with ``e`` or ``E``. ``f`` : decimal floating point ``g,G`` : use the shorter of ``e,E`` or ``f`` ``o`` : signed octal ``s`` : str of characters ``u`` : unsigned decimal integer ``x,X`` : unsigned hexadecimal integer This explanation of ``fmt`` is not complete, for an exhaustive specification see [1]_. References ---------- .. [1] `Format Specification Mini-Language <http://docs.python.org/library/string.html# format-specification-mini-language>`_, Python Documentation. Examples -------- >>> savetxt('test.out', x, delimiter=',') # x is an array >>> savetxt('test.out', (x,y,z)) # x,y,z equal sized 1D arrays >>> savetxt('test.out', x, fmt='%1.4e') # use exponential notation """ with get_file_obj(fname, 'w') as fh: X = np.asarray(X) # Handle 1-dimensional arrays if X.ndim == 1: # Common case -- 1d array of numbers if X.dtype.names is None: X = np.atleast_2d(X).T ncol = 1 # Complex dtype -- each field indicates a separate column else: ncol = len(X.dtype.descr) else: ncol = X.shape[1] # `fmt` can be a string with multiple insertion points or a list of formats. # E.g. '%10.5f\t%10d' or ('%10.5f', '$10d') if isinstance(fmt, (list, tuple)): if len(fmt) != ncol: raise AttributeError('fmt has wrong shape. %s' % str(fmt)) format = delimiter.join(fmt) elif isinstance(fmt, str): if fmt.count('%') == 1: fmt = [fmt, ]*ncol format = delimiter.join(fmt) elif fmt.count('%') != ncol: raise AttributeError('fmt has wrong number of %% formats. %s' % fmt) else: format = fmt # handle names if names is None and X.dtype.names: names = X.dtype.names if names is not None: fh.write(delimiter.join(names) + '\n') for row in X: fh.write(format % tuple(row) + '\n')

Last update: Jun 14, 2024